Spoof Surface Plasmon Polaritons Supported by Substrate Integrated Waveguide with Arrays of Holes

This paper presents an approach to develop spoof surface plasmon polaritons (SSPPs) in substrate integrated waveguides (SIWs) with simple geometries (arrays of rectangular holes). Dispersion properties of both SSPPs based on a SIW with a rectangular hole and the traditional SSPPs based on a single-conductor metallic strip with the same hole are compared. Moreover, a smooth transition built by stepped impedance transmission lines with gradient holes is designed for high-efficiency mode conversion. Consequently, an SSPP waveguide is constructed by a SIW with uniform holes and the proposed transition, and the frequency responses of the waveguide are simulated for validation. The simulated bandwidth can reach as up to 100.1% covering a range from 4.34 to 13.05 GHz, which agrees well with the dispersion diagram.